Step A: A solution of 1-thiazol-2-ylacetophenone (2.00 g, 15.7 mmol) in anhydrous THF (8 mL) was slowly added dropwise to a solution of 97% tribromophenyltrimethylammonium (6.08 g, 15.7 mmol) in anhydrous THF (32 mL). The reaction mixture was heated at 35 °C with stirring for 3 h, followed by standing overnight. After completion of the reaction, the solid was removed by filtration and the filtrate was concentrated under reduced pressure to give the crude product. The crude product was dissolved in dichloromethane (CH2Cl2) and purified by silica gel column chromatography (eluent: 20/80 ethyl acetate/petroleum ether) to afford 2-bromo-1-thiazol-2-ylacetophenone (2.85 g, 88% yield) as a solidified oil.1H-NMR (CDCl3) δ: 8.03 (d, 1H, J = 2.8 Hz, -S-CH=CH-N=); 7.75 (d, 1H, J = 2.8 Hz, -S-CH=CH-N=); 7.75 (d, 1H, J = 2.8 Hz, -S-CH=CH-N=). ); 7.75 (d, 1H, J = 2.8 Hz, -S-CH=CH*-N=); 4.70 (s, 2H, CH2).
